The disclosed subject matter relates generally to manufacturing and, more particularly, to a method and apparatus for dynamically determining tester recipes.
There is a constant drive within the semiconductor industry to increase the quality, reliability and throughput of integrated circuit devices, e.g., microprocessors, memory devices, and the like. This drive is fueled by consumer demands for higher quality computers and electronic devices that operate more reliably. These demands have resulted in a continual improvement in the manufacture of semiconductor devices, e.g., transistors, as well as in the manufacture of integrated circuit devices incorporating such transistors. Additionally, reducing the defects in the manufacture of the components of a typical transistor also lowers the overall cost per transistor as well as the cost of integrated circuit devices incorporating such transistors.
Generally, a set of processing steps is performed on a wafer using a variety of processing tools, including photolithography steppers, etch tools, deposition tools, polishing tools, rapid thermal processing tools, implantation tools, etc. During the fabrication process various events may take place that affect the performance of the devices being fabricated. That is, variations in the fabrication process steps result in device performance variations. Factors, such as feature critical dimensions, doping levels, contact resistance, particle contamination, etc., all may potentially affect the end performance of the device.
After fabrication of the devices is complete, each wafer is subjected to preliminary functional tests, commonly referred to as final wafer electrical tests (FWET) that evaluate test structures on the wafer and SORT tests that evaluate each die. Wafers that pass these tests are then cut to singulate the individual die, which are then packed in substrates. Packed die are then subjected to additional tests against the specification of customers' orders to determine performance characteristics such as maximum operating speed, power, caches, etc.
Exemplary tests include initial class tests (ICL) that are preliminary tests for power and speed. ICL testing is usually followed by burn-in (BI) and post burn-in (PBI) tests that test packaged die under specified temperature and/or voltage stress, and automatic test equipment (ATE) tests that test die functionality. Then, packaged die with different characteristics go through system-level tests (SLT) in which they are tested against customer requirements on specific electrical characteristics. In SLT, packaged die are tested in an actual motherboard by running system-level tests (e.g., variance test programs). After completion of the testing, the devices are fused, marked, and packed to fill customer orders. This back-end processing is commonly referred to as the test, mark, pack (TMP) process.
Typically, test instructions and acceptance criteria are defined for each test program implemented by a tester. These programs are typically stored in a central database and essentially static. A tester may periodically download the most current “golden” test program from a central data store prior to implementing the test. The recipe database allows revision and configuration control. However, the test program is executed without change once it is downloaded by the tester. Hence, the test flow and acceptance criteria employed by the tester are static.
Device testing is often an iterative process that involves testing the device using various frequency and voltage ranges to attempt to accurately determine the maximum frequency and minimum voltage capabilities of the device. The length of the test program and the resulting throughput of the tester is thus directly proportional to the number of test iterations required. Hence, programs implemented for testing devices are typically lengthy and detailed. These test programs are typically written at the beginning of the device life cycle so that the new device may be thoroughly exercised and characterized. Generally, the test program does not change significantly once it is implemented. The length of time required to implement these tests is a throughput limiting factor in the production flow.
This section of this document is intended to introduce various aspects of art that may be related to various aspects of the disclosed subject matter described and/or claimed below. This section provides background information to facilitate a better understanding of the various aspects of the disclosed subject matter. It should be understood that the statements in this section of this document are to be read in this light, and not as admissions of prior art. The disclosed subject matter is directed to overcoming, or at least reducing the effects of, one or more of the problems set forth above.